Tonight’s Code via RViews: http://bit.ly/2AE6En3

Motivation

the Recipe

Software–seriously, keep up-to-date

install.packages("pacman")
p_load(rmarkdown, knitr, questionr, tidyverse, sessioninfo, update = TRUE)

Make sure RStudio is new enough to get previews

the Data

My guide works with four Pew Research Political Surveys: January, March, August, and October 2016. Data are free and easy to download (but account is required).

Configuring the RMarkdown Template

Building the Template

The Template

I find it easiest to write a fully working example and then make little changes as needed so that knitr::render() can loop over the data sets. First things first.

survey <- read.spss("Jan16/Jan16 public.sav", to.data.frame = TRUE)

Summary stats can easily be inserted into the text like so.

Making Tables with Kable

kable(wtd.table(survey$ideo, survey$sex, survey$weight)/nrow(survey), digits = 2)

Using Kable in a Loop

x <- names(survey)[grep("q2[[:digit:]]", names(survey))]
x

 [1] "q20"  "q21"  "q22a" "q22b" "q22c" "q22d" "q22e" "q22f" "q22g" "q22h"
[11] "q22i" "q25"  "q26"  "q27"  "q28" 

y <- c("ideo", "party")

for (i in x) {
    for (j in y) {
        cat("\nWeighted counts for", i, "broken down by", j, "\n")
        print(kable(wtd.table(survey[[i]], survey[[j]], survey$weight)))  # requires asis=TRUE
        cat("\n")  # break out of table formatting
    }
    cat("\\newpage")
}

Adding a plot

PA <- ggplot(survey) + geom_bar(aes(q1, y = (..count..)/sum(..count..), weight = weight, 
    fill = q1)) + facet_grid(party.clean ~ .)
PA <- PA + theme_minimal() + theme(strip.text.y = element_text(angle = 45)) + 
    xlab("") + scale_y_continuous(labels = scales::percent) + ylab("Percent of Country") + 
    ggtitle("Presidential Approval: January 2016")
PA

Adapting the Template with Parameters

The next step is to add a parameter with any variables you need. The parameters will be controlled by the R script discussed in a moment.

params:
  spssfile: !r  1
  surveywave: !r 2016

Parameterizing (cont’d)

PA <- PA + ggtitle(paste("Presidential Approval:", params$surveywave))

dir(pattern = ".sav", recursive = TRUE)

[1] "http___www.people-press.org_files_datasets_Aug16/Aug16 public.sav"
[2] "Jan16/Jan16 public.sav"                                           
[3] "March16/March16 public.sav"                                       
[4] "Oct16/Oct16 public.sav"                                           

Automating with knitr

library(pacman)
p_load(knitr, rmarkdown, sessioninfo)

setwd("/users/mohanty/Desktop/pewpolitical/")

waves <- c("August 2016", "January 2016", "March 2016", "October 2016")  # for ggtitle, etc.

for (i in 1:length(waves)) {
    render("pewpoliticaltemplate.Rmd", params = list(spssfile = i, surveywave = waves[i]), 
        output_file = paste0("Survey Analysis ", waves[i], ".pdf"))
}

session <- session_info()
save(session, file = paste0("session", format(Sys.time(), "%m%d%Y"), ".Rdata"))

A Little Version Control

If a package stops working install_version (from library(devtools)) installs older versions.

s <- session_info()
s$platform$version

[1] "R version 3.4.2 (2017-09-28)"

s$platform$os

[1] "macOS Sierra 10.12.6"

head(s$packages)

 package    * version date       source        
 assertthat   0.2.0   2017-04-11 CRAN (R 3.4.0)
 backports    1.1.1   2017-09-25 CRAN (R 3.4.2)
 bindr        0.1     2016-11-13 CRAN (R 3.4.0)
 bindrcpp     0.2     2017-06-17 CRAN (R 3.4.0)
 broom        0.4.2   2017-02-13 CRAN (R 3.4.0)
 cellranger   1.1.0   2016-07-27 CRAN (R 3.4.0)

Thanks!